Fig. 1. Comparison of effects of VEGF-A/FGF-2 co-stimulation with those of VEGF-A or FGF-2 stimulation alone in a Matrigel plug assay in vivo. (A-C) Matrigel plugs mixed with 1 µg/ml FGF-2 and 200 ng/ml VEGF-A (A), 1 µg/ml VEGF-A alone (B), or 1 µg/ml FGF-2 alone (C) were subcutaneously injected into the abdomen of mice. After 7 days, gels were extracted and examined after Hematoxylin and Eosin (H & E) staining (A-C upper rows; Scale bars: 60 µm), and by immunohistochemistry with anti-PECAM1 or CD34, SMA, or by intravenously administrated FITC-conjugated dextran, as indicated in the figure (lower rows; scale bars: 20 µm). (D,E) Quantification of the formation of new vessels in Matrigel plugs by their lengths is shown. Vessels and vessel-like structures were classified into three categories as follows: mature blood vessels containing red blood cells (RBCs) (red bars), cavities surrounded by cells but without RBCs (light blue), and cells arraying in line but without cavities (blue). *P<0.05, **P<0.01 by Student's t-test. Corresponding figures for NG2 and desmin staining, and F4/80 staining under the VEGF-A-stimulated condition are shown in Figs S1 and S2, respectively.